ShortMag

I went with Timbren’s on my AT4. Rarely notice them when daily driving. They make a huge difference in squat when loaded. It’s nothing for me to put a pallet with 2000lbs of material in my bed now. Yes I know that’s over payload capacity

Ridge Grapplers at 38-40psi. 50k miles and still going strong

I’m over 32k on my ‘19 6.2 and had 90k on my ‘14 6.2 before that. Loved them both and no significant issues with either truck. Would buy another tomorrow in a heartbeat

Boost kit is great. I got the “all lights” kit. Fogs on with headlights and stay on with hi beams.

Thanks Kyle. Last question - is the picture of the spring with the load of stone in the bed or unloaded? I assume unloaded. Thanks again

Kyle, are those medium duty Sumo’s? a yard of stone is supposed to be 2400 pounds. Is your truck a half ton? currently I limit my loads in my half ton to 1500 pounds. But it sure would be easier to load a 2000 pound pallet of material (corn or fertilizer) at a time yeah, I know that’s over payload capacity

Considering Sumo Springs for my 2019 AT4. I carry 1500lbs + of deer corn or fertilizer in my bed periodically and the rear sag is bad. I only have to drive about 10 miles loaded like that Anyone with experience using Sumo Springs to lessen sag when the bed is loaded?

40-45

3rd post down in this thread. Not my truck, but looks just like it. I got them based on this picture and have not regretted it https://www.gm-trucks.com/forums/topic/223068-biggest-tires-on-at4-18-wheels-with-no-modification-or-wheel-change/#comments

My stock AT4 with 18s has 285/70 Ridge Grapplers. You may be able to go a hair bigger but not much and you’ll pay a big price in tire weight

Put them on my 2014 and loved them. Until I replaced them with BFG KO2s at 60k. Then I realized how loud and harsh they were. went with ridge grapplers on my 19

16 months and 25000+ miles on my ‘19 AT4. Have not had any of the problems you have. Absolutely love the truck

You’ll love them. 25k miles on mine on my stock AT4. Look great and don’t kill the mileage as bad as 35s

2019 Sierra AT4 with about every option in terms of technology packages ordered the $20 Boost Auto Fog light mod. This turns on fog lamps any time parking lights are on, including with high beams very clear installation videos on YouTube. I’d never done something like this before but tackled it in about 10 minutes and it seems to work fine i have not driven at night yet to test with Intellibeam but with my understanding of how it works, that shouldn’t change anything so this mod has given me everything the “6 high/all lights” mod plus my fogs automatically come on with my parking lamps highly recommend that is all

Got rid of oem tires immediately so my only point of comparison is my 14 denali with a level, 20” wheels and tires just shy of 35”. My AT4 rides a lot better than my old truck. I like the bigger sidewall that comes with an 18” wheel. I really can’t compare to factory though